{"id":3495,"date":"2026-10-29T12:22:38","date_gmt":"2026-10-29T04:22:38","guid":{"rendered":"http:\/\/www.aisyaavicenna.com\/blog\/?p=3495"},"modified":"2026-10-29T12:22:38","modified_gmt":"2026-10-29T04:22:38","slug":"what-size-feeder-cable-for-50-amp-rv-4845-ea84a4","status":"publish","type":"post","link":"http:\/\/www.aisyaavicenna.com\/blog\/2026\/10\/29\/what-size-feeder-cable-for-50-amp-rv-4845-ea84a4\/","title":{"rendered":"What size feeder cable for 50 amp RV?"},"content":{"rendered":"

If you\u2019ve ever stood behind an RV at a campground, waiting for it to hook up to power, you\u2019ve probably glanced at the thick cable snaking between the RV and the pedestal and wondered: \u201cHow did that get sized that way?\u201d As a feeder cable supplier who\u2019s worked with RV techs, campground owners, and full-time RVers for over a decade, I get these questions all the time\u2014especially around 50 amp RV setups, which are one of the most common upgrades for larger travel trailers, fifth wheels, and Class A motorhomes. Feeder Cable<\/a><\/p>\n

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Let\u2019s cut through the noise: a 50 amp RV doesn\u2019t just need any cable. It needs a cable sized to handle the electrical load, keep your rig safe, and avoid the kind of heat damage that can turn a weekend trip into a costly emergency. Too small, and you risk voltage drops, overheating, even fires. Too big, and you\u2019re wasting money on material you don\u2019t need. Today, I\u2019m breaking down exactly what size feeder cable works for 50 amp RVs, why it matters, and what I recommend after years of seeing what holds up on the road.<\/p>\n

First, let\u2019s clarify what \u201c50 amp RV\u201d actually means. A lot of people hear \u201c50 amp\u201d and assume it\u2019s a single 50 amp circuit, but that\u2019s not how RV electrical systems work. Most modern 50 amp RVs are 240V split-phase systems. That means they have two 120V legs, each rated at 50 amps, totaling 10,000 watts of power (50 amps x 200V, if we\u2019re doing the math). You use one leg for your air conditioner, microwave, and outlets, and the other for your water heater, refrigerator, and charging stations. So when we talk about feeder cable for a 50 amp RV, we\u2019re not just sizing for 50 amps total\u2014we\u2019re sizing for the continuous load that will run through that cable.<\/p>\n

That brings us to the NEC: the National Electrical Code, the rulebook that governs all electrical installations in the U.S. (and is referenced in most other countries for RV and campground power). NEC rules are non-negotiable here. For continuous electrical loads\u2014like the ones your 50 amp RV will pull (your AC runs for hours, your fridge is on nonstop)\u2014the code requires that feeder cables are sized to handle at least 125% of the load. For a 50 amp RV, that means 50 amps x 125% = 62.5 amps. That\u2019s the minimum current your cable needs to handle without overheating.<\/p>\n

Now, let\u2019s translate that into cable gauge. Cable gauge is the measure of a wire\u2019s thickness; the lower the number, the thicker the wire. For copper wire, which is the most common and durable for RV use, let\u2019s go over the numbers that apply here. I\u2019ve seen a lot of campgrounds and RVers cut corners with a 6 gauge cable for 50 amp setups, but that\u2019s a mistake. For 600V copper feeder cable (the standard for RV power), the ampacity (the amount of current a wire can safely carry) is roughly:<\/p>\n